1. Field of the Invention
The present invention relates to heat activated transfers and appliqués and, particularly, to a light-weight breathable heat-transfer comprised of numbers, letters, logos, graphics, and other indicia which do not change the physical and visual characteristics of performance fabrics to which they are applied, including breathability, moisture-wicking characteristics, stretch and recovery, and launderability.
2. Description of the Background
Manufacturers of performance apparel, uniforms, swimwear, and sports accessories use various methods to apply a variety of indicia, such as text, numbers, logos, graphics, and other indicia, to garments and textiles for decoration and identification, among other things. Common application technologies include silk-screening, screen-printing, sonic welding, direct embroidery, and heat activated transfers.
Silk-screening of logos or emblems is commonly used, but this process does not result in a product that withstands repeated stretching, and is complex and time-consuming. In addition, the designs created by silk-screening are flat, lack texture, and do not withstand repeated stretching or industrial or home washings. Consequently, many companies prefer embroidery as their primary method for applying decoration and identification.
Sonic welding is another method used to apply decoration and identification to garments and textiles. The nature of a sonic-welded bond is a fusing of materials which results in a rigid material interface. The rigid interface causes cracking and potential sheering when stretched, and can debond after repeated home and industrial laundering. Sonic welding allows texturing, but also requires chemical compounds that some companies find unacceptable. Moreover, sonic welding requires the creation of unique, expensive special dies for any design to be applied. Consequently the process is slow, relatively expensive, and not well-suited for the performance apparel industry and its small-batch production/quick-changeover requirements. Indeed, this process typically is not used by the uniform industry for these reasons. Embroidery has instead become the primary method for applying decoration and identification.
Embroidery is typically performed by a machine that applies stitching of various colors and styles to fabric to create a design. Embroidered designs have a much greater aesthetic value, and stand repeated home and industrial launderings. Yet this too is a complex, time-consuming process. While appliqués stitched have more potential to stretch mechanically then welded bonds they are still limited by the sewn threads which constrain elongation and can break if stretched.
Thermally activated adhesive coatings are also used to apply appliqués to garments and textiles. One common type of appliqué, typical of sports jersey and uniform, numbering and lettering, is a layered appliqué comprising a solid first base layer that defines a numeral or letter and one or more top layers that are the same shape, but smaller than the layer below it, thereby creating a three dimensional appearance. Typically, each additional top layer is stitched to the layer below it. On the back of the solid base layer is a layer of thermally activated adhesive that covers the entire back surface. The solid fabric layers in combination with the solid adhesive coating result in a rigid, thick and relatively heavy, and moisture/air impermeable appliqué. Thus, when such an appliqué is applied to a substrate that is more flexible, lighter, or more breathable than the appliqué itself, the substrate's characteristics are lost.
The destruction or interference with the characteristics of the underlying fabric is a significant disadvantage, especially in the context of performance apparel with moisture-wicking and/or breathability characteristics, because the appliqué undermines the garment's comfort and performance. In addition to unfavorably changing the physical characteristics of the substrate, these appliqués also change the substrate's visual characteristics, such as the amount of drape. Another problem to overcome particularly in contact sports such as football and hockey is the potential for the garment and appliqués to be pulled causing a sheer which can break the bond between garment and appliqué whether sewn or adhered with an adhesive.
It would be greatly advantageous to provide a heat sealed appliqué that can be applied to any garment or textile without obstructing any performance characteristics of the garment or textile, and which is therefore particularly well-suited for lightweight, breathable and/or moisture-wicking textiles commonly used in performance sports apparel.